for this.
-- Fio Cattaneo
Universal AC, can Entropy be reversed? -- "THERE IS AS YET INSUFFICIENT
DATA FOR A MEANINGFUL ANSWER."
-Original Message-
From: time-nuts On Behalf Of John
Moran, Scawby Design
Sent: Monday, 8 February, 2021 09:37
To: time-nuts@lists.febo.com
Subject: Re: [time-
time-nuts" schrieb am 08.02.2021
23:59:07:
> Von: joekok...@epios.eu
> An: time-nuts@lists.febo.com
> Datum: 09.02.2021 00:05
> Betreff: Re: [time-nuts] Daft idea with the National Grid
> Gesendet von: "time-nuts"
>
> Dear all,
>
> it is quite an inter
Dear all,
it is quite an interesting premise. I think one of the challenges is to
even measure these small deviations in frequency. The time correlation
can be achieved with GNSS but the actual determination of the
zero-crossing might be the problem. I think the ZCD must be better than
100ns
Years ago I recall reading accounts of efforts in the U.S. and perhaps Canada
to track down the cause(s) of small but noticeable changes in the frequency of
certain regional power grids that seemed to occur at more or less the same time
each day.
Mark Spencer
m...@alignedsolutions.com
604
That was some heavy-weight receptionist! :-)
Thanks for the feedback.
John
> On 8 Feb 2021, at 17:58, Poul-Henning Kamp wrote:
>
>
> John Moran, Scawby Design writes:
>
>> "If you happen to own something like a steel mill running electric
>>
>> furnaces or an aluminum refinery, so
Hi,
On 2021-02-08 18:37, John Moran, Scawby Design wrote:
> On Sun, 7 Feb 2021 20:45:57 -0800
> Jim Lux said -
>
>
> "If you happen to own something like a steel mill running electric
>
> furnaces or an aluminum refinery, so you can manipulate the load..."
>
> Sometime in the late '80s, my first
John Moran, Scawby Design writes:
> "If you happen to own something like a steel mill running electric
>
> furnaces or an aluminum refinery, so you can manipulate the load..."
>
> Sometime in the late '80s, my first decent sized computer system came on line
> [...]
We had the same
On Sun, 7 Feb 2021 20:45:57 -0800
Jim Lux said -
"If you happen to own something like a steel mill running electric
furnaces or an aluminum refinery, so you can manipulate the load..."
Sometime in the late '80s, my first decent sized computer system came on line
at a telecom factory in
Hi,
On 2021-02-08 12:31, Hal Murray wrote:
> andy.g4...@gmail.com said:
>> I can probably measure the grid frequency to a few micro Hz over a period
>> of tens of seconds. So I make a continuous recording of this, averaged over
>> say 10 second periods. Now take a 7kW load (the maximum
I'm not convinced they will be impressed by your scheme for ultra VLF
signalling Andy but it'd make a nice Radcom article
On Sun, 7 Feb 2021, 21:44 Andy Talbot, wrote:
> The UK has a standalone frequency locked grid supply, nominal 50Hz, which
> typically wanders +/- about 0.15Hz RMS over
Hal Murray writes:
> I'd expect an ADEV type pattern. For long tau, the wander in the system will
> dominate. We have lots of long term data so should be able to plot that part
> of the graph.
I did that some years ago: The Nordic grid bottomed out around 1e-10, with
a frequency
andy.g4...@gmail.com said:
> I can probably measure the grid frequency to a few micro Hz over a period
> of tens of seconds. So I make a continuous recording of this, averaged over
> say 10 second periods. Now take a 7kW load (the maximum reasonably possible
> on a domestic circuit) and switch
Lux, Jim writes:
> If you happen to own something like a steel mill running electric
> furnaces or an aluminum refinery, so you can manipulate the load...
More scary: Several independent studies have shown that even relatively
moderate bot-nets in the hands of somebody who knows the
Andy Talbot writes:
> Not sure what the time constant of the grid control is, but for* small
> signals* I doubt it can be faster than a few minutes.
There are generally spaking two time constants, the physical and the human.
The physical time constants are probably best understood as
On 2/7/21 3:28 PM, Dana Whitlow wrote:
Not daft at all, Andy. Closely related would be measurements of phase
change between
near the switched load and far away, over a stretch of a few system time
constants.
This would be more challenging, but perhaps doable.
Dana K8YUM
If you happen to
Am 08.02.21 um 00:11 schrieb Philip Gladstone:
As an amateur radio guy, I can't help wondering whether I could use this as
a *very* low bit rate channel across the country.
I have done navigation _for_ tv and phone sats, and the spread
navigation signals are just 20 dB under the MPEG data
Not daft at all, Andy. Closely related would be measurements of phase
change between
near the switched load and far away, over a stretch of a few system time
constants.
This would be more challenging, but perhaps doable.
Dana K8YUM
On Sun, Feb 7, 2021 at 3:44 PM Andy Talbot wrote:
> The UK
As an amateur radio guy, I can't help wondering whether I could use this as
a *very* low bit rate channel across the country.
Philip
On Sun, Feb 7, 2021 at 4:44 PM Andy Talbot wrote:
> The UK has a standalone frequency locked grid supply, nominal 50Hz, which
> typically wanders +/- about
The UK has a standalone frequency locked grid supply, nominal 50Hz, which
typically wanders +/- about 0.15Hz RMS over several minutes , with
occasional short-lived excursions out to 0.2 or 0.3Hz. Average number of
cycles per period generally is normalised to 50Hz after a few days.
The typical
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